Portable derrick



P A. B. KINTZLEY 1,974,463

PORTABLE DERRICK Filed June 24, 1933 I ATTORNEYS.

Patented Sept. 25, 1934 1,974,463 PORTABLE DERRICK Alfred B. Kintzley,Burlingame, Calif. Application June 24, 1933, Serial No. 677,500 8Claims. 01. 254-4391 This invention relates to portable derricks and hasfor its objects adevice of this character especially designed for use inconnection with automobiles in such work as raising the transmission orclutch up through the floor opening of the drivers compartment etc., andwhich will meet the requirement presented by various makes ofautomobiles. Other objects are extremely simple, cheap, yet rigidconstruction. in such a device.

Fig 1 is a side elevation of my improved derrick.

Fig. 2 is a plan view of the derrick. V, Fig. 3 is an enlarged side viewof the hand hoist slidably mounted onythe adjustable boom of thederrick. I

Fig. 4 is a sectional view of Fig. 3 line 4-4 thereof. V I

Fig.5 is an enlarged vertical section of the adjustable strut engagementon the mast of the derrick. V

Fig. 6 is an enlarged cross section of the weight clamped on the hoistcable just above the'hook. Fig. -7 is an enlarged broken side view ofone of the legsof the derrick-showing its connection to the mast, alsothe supporting casters.

In further detail my improved derrickconsists of two horizontallydisposed diverging legs 1, a vertical mast 2, and a boom 3, p-ivotallysecured at 4 to the top of the mast and extending laterally therefromalong a line midway between the legs 1, as best shown in Fig. 2 and in amanner so that the outer end of the boom may swing in a vertical are 5and be held firmly at any point lby a strut 6 pivoted at its upper endat '7 to a casting 8 which is clamped to the boom, and with its lowerend provided with tapered shoe 8 engageable with any of the teeth 9 of aratchet plate 10 secured to the mast. The teeth 9 are '1 formed at thebottom of a groove in the plate so that the sides of the grooveeffectually hold the strut from becoming accidentally displaced in asidewise direction, while a wire sprng 11 at the upper end of the strutkeeps it resiliently forced ,into contact with the teeth.

The legs, mast and boom are preferably all made of pipe, and where themastand two legs join is an angle casting 12 provided with half roundseats 13 for the pipes and sockets 14 snugly lembracing the ends of thepipes, and all held in rigid assemblage as by means of rivets 15 orwelding in place.

Three floor casters 16 form a tripodal support and the casters at theouter end of the legs are 7 mounted in blocks 1'7 riveted or otherwisesecured as seen from In thedrawing accompanying thisspecification to theextreme ends of the legs, while the caster, at the mast juncture ismounted in a boss 18 in the angle. joint casting 12, all casters beingheld; from dropping out by any suitable means such as thescrews 19. j

The boom is provided with a casting 20 at itsouter end forming twobearing sides between which is a 'head.pulley 21 over which the hoistrope 22 passes, and at the extreme outer end of the casting 20 isan eye23 or equivalent device for suspending an electric lamp above the work,as it is always dark in working on automobile transmissions, clutches,fiywheels, etc. Rope 22-carries a hook 37 at its free end and just-abovethis a split weight 24 clamped over the doubled back end of the rope soas to suspend the hookand also provide weight enough to pull the ropedownward as it is unrolled from the drum 25 of a hand hoist carriedbetween the arms 26 of a bracket 27 carried on the boom 3 and clampedthereto by cooperation with casting 8 as indicated in Fig. 3.- The drumis secured to a shaft 28 as is alsoa ratchet wheel 29. This wheel 29 hastwo sets of ratchet teeth, one set 30 on its periphery and the other set31 on its side. Teeth 30.are engaged by a spring pawl 32 topreventreverse rotation of the drum and side teeth 31 are ene gaged by aspring pawl 33 carried, by acrank handle 34 loosely mounted on the endof the drum shaft 28 and prevented from coming off by a collar or nut35. A handle 36 connected to pawl 32 serves for lifting it out ofengagement so that the drum may be permitted to unwind (under control ofthe hand crank). With the above arrangement it will be observed that thehand hoist may be adjusted to various positions along the boom, alsothat this will vary the angle of projection of the boom, but that aseparate adjustment of the angle of the boom is had in the ratchet strutconnection to the mast.

In using the derrick the two legs are rolled under an automobile and theboom is projected through the open doorway (if a closed car) into thedrivers compartment, the hoist is positioned in best place to avoid thedoor and permit most efficient operation and the boom given the properangle to clear the dash or instrument board of the car. An electric bulbis suspended from the eye 23 to light the Work. The design of thederrick with its handoperated hoist drum on the boom itself provides foroperation by one mechanic from his place inside the car by merelyoscillating the ratchet handle without even standing up, and afterraising the machinery, he can back the derrick out to carry the loadthrough the doorway. The spread legs of the derrick being free fromcross braces provide a clear space for depositing the load upon thefloor or lifting it therefrom.

Having thus described my improvements, what I claim is:

1. A portable derrick comprising a, pair of horizontally extending Vlegs close to the floor, a mast rigidly secured at the juncture of thelegs, a vertically adjustable boom pivoted to the top of the mastextending laterally on a line between the legs, a hand hoist mounted onsaid boom forwardly of said mast provided with a hoist rope ex:- tendingover the end of said boom.

2. A portable derrick comprising a mast, a pair of horizontallyextending legs close to the floor diverging from said mast, a boomextending laterally from said mast above the legs, and a handoperatedhoist mounted on said boom forward. of

the mast so as to be accessible to an operator under the boom.

3. In a portable derrick provided with a boom projecting laterally froma mast, a hoist drum mounted on said boom forward of the mast with itsrope extending over the end of the boom, and a ratchet hand crank onsaid drum permitting operation of the drum by oscillating the hand crankfrom a position below the weight-supporting end of said boom.

4. A portable derrick comprising a pair of horizontally extending vlegs, a mast at the juncture ofthe legs, a boom pivoted to the top ofthe mast extending laterally on a line between the legs, a hand hoistmounted on said boom provided with a'hoist rope extending over the endof said boom, said hand hoist including a rotatable winding drum, aratchet Wheel locking the drum against reverse rotation, a second seriesof ratchet teeth on said Wheel, and a freely revolvable hand crankprovided with a pawl engaging said ratchet teeth. 5. A portable derrickcomprising a pair of horizontally extending V legs close to the floor, amast rigidly secured at the juncture of the legs, a boom pivoted to thetop of the mast extending laterally on a line between the legs, amanually adjustable strut extending from the boom to the mast in amanner to be accessible for manipulation to an operative under the loadsupporting end of the boom, the legs and mast being of pipe, and

legs, a pulley on the boom adjacent the outer end thereof, a hand hoistmounted on said boom provided with a rope extending along the boom andover the pulley, said hand hoist being positioned at a pointon the boomintermediate the pivoted end of the boom and the pulley, whereby it isaccessible to an operator positioned adjacent said pulley.

7. A portable derrick comprising a pair of horizontally extending V legspositioned close to the floor, a generally vertically extending mastadjacent the juncture of the legs, a boom pivoted at one end adjacentthe upper end of the mast extending laterally over the area between thelegs, a pulley on the boom adjacent the outer end thereof, a hand hoiston the boom provided with a rope extending along the boom and over'thepulley, said hand hoist being positioned on the boom at a pointintermediate'th e pivoted end of theboom and the pulley whereby it isaccessible to an operator positioned adjacent said pulley, a manuallyadjustable strut for the boom extending from the mast to a point on theboom adjacent the hand hoist and the vertical area between that portionof the boom between the hoist and'pulley and the legs being free foradmission of a foreign object.

8. A portable derrick comprising a pair ofhorizontally extending V legsclose to the floor, a mast rigidly secured at the junction of the legs,a boom pivoted to the top of the mast extending laterally on a linebetween the legs, a manually adjustable strut extending from the boom tothe mast in a manner to be accessible for manipulation to an operativeunder the load-supporting end of the boom, a series of teeth along saidmast, and a spring acting against said strut forcing it into engagementwith said teeth.

ALFRED KINTZLEY.

